alt Hacker NewsESA is going to remain on the mission/payload side. ArianeSpace makes sense as a launch services provider handling everything that's not the rocket. ArianeGroup (the company that actually builds the rockets) will just become the French rocket company that will end up competing with the Italian and German ones.
Like most "small rocket companies" they'll come to the conclusion that they need bigger rockets to launch bigger payloads. Rockets that compete directly with Ariane 6. With some luck these will be reusable to, making Ariane 6 and ArianeSpace obsolete.
ESA and ArianeSpace will slowly but surely decay into obsolescence.